Original post by archon256 on the old forums (forumer).Most formatting is lost.-WolfieeifloW

crŭcĭātor, -ōris, m. [crucio], a tormentor, torturer.

This is a melee assassin guide focusing on Crucify as the primary attack, fire procs, and life-on-striking. You'll do tremendous damage with fire procs, and rapdily regain life from Queen of Blades and Crucify.

Pros High damage High mobility Can farm most of the ubers Rapidly regains life Easy leveling

Cons Low defense and life for a melee build Expensive gear Fire-immunes die a bit slower

About 'Life On Striking' The survivability of this build revolves around this modifier. With Adramalech and Norrec's Targe, you gain 20 life on striking. This means that for every weapon attack of yours that hits the target, you gain 20 life. This includes every Crucify spike, every Fortress arrow, every QoB blade, as well as the melee hit portion of Crucify.

Also, Hades Gate hits every monster on the screen. This can be used in crowded areas to quickly fill your HP bulb.

Unlike Leech, Life On Striking is unaffected by difficulty. Also, unlike leech, it works against physical immune monsters as well. This greatly helps your survival in some of the uberquests where the monsters are under an immunity shield, such as Azmodan's Reliquary and Cathedral of Vanity.

Don't underestimate Life Leech though. With lvl 44 Doom from our Amulet, we'll be leeching ~4.4k*(1/50)*(1/100) = ~0.88 life per point of leech on striking (since life leeched from Doom doesn't depend on the damage of the attack itself, or the weapon modifier). So get a bit of Life Leech as well (I have 12%, including charms).

Gear

Core Weapon: Adramalech "Krys" Toraja Great Runeword in a Sacred Scissors Katar Belt: Nero "Auhe" Toraja Great Runeword Amulet: Rare amulet with 15% ctc lvl 44 Doom on kill, +2/3/4 skills, MO'd with -Fire Res and +Fire Spell damage Jewels: Lem crafts with 5+ to all attributes, +1% to all attributes and +3% to Fire Spell damage and Lem crafts with 5+ to all attributes, +1% to all attributes/1-2% to one attribute and 20+% to two resistances, only use enough of these to max your resists.

The Adramalech runeword grants you +10 Life On Striking, as well as a nifty Flamefront On-Attack proc. The Condemned reanimates don't contribute much to damage, but they help a bit in tanking. Nero is an incredibly powerful runeword, and we shall make full use of it. Path of Flames will contribute enormously to our total damage output, and the Fortress procs will help us a lot in regaining life. The +Fire Spell damage will boost all our fire procs. We use Lem craft jewels instead of the typical Ber craft ones because we don't need life leech. The Dexterity they give helps us to achieve high Block. 3% Fire Spell damage is enough for our purposes, instead of the 6% we could have had from Zod crafts. Don't forget to use the Lucky Upgrade on your jewels!

Bloodlust and Mark of the Wild from the Claws on switch increases our overall damage, including the damage of our fire spells. The two pieces of armor mentioned above both increase our fire spell damage as well as provide additional spell procs. The choice of armor is largely irrelevant though, feel free to use your favorite RW/Set/SU armor here. Norrec's Targe SU Shield is excellent for our build, and is almost compulsory. It increases our life on striking to 20 overall, adds two more fire procs, gives us a tanky reanimate and helps us regain even more life with the Life On Kill modifier. I highly recommend you try to obtain it either through farming or trading. We choose Eidolon for the excellent defense bonus, resistances and stat bonus it provides. Snowsquall gloves are useful for the "Slows Target by 20%", a modifier we lack otherwise. It also provides an alternate source of elemental damage to deal with Fire + Physical Immunes. Craton boots provide lots of defense once fully MO'd. We use Empyrean bands instead of other popular rings like SotNKs since we don't benefit much from +skills, and since we can MO them to help us get to -100 to enemy Fire Res.

Skill build Pretty simple, your basic Crucifysin skill build. smax Crucify - More Doom damage from your amulet, reduced mana cost per level while leveling smax Way of the Phoenix - More fire damage per attack, more fire spell damage for your fire procs 1 point in Beacon - The damage WotG adds is negligible compared to the rest of our damage sources, and Phase Bomb will kill us if we try to use it. Beacon is very useful in a lot of the uberquests as well. 20+ points in Shadow Refuge - Enough to get us to 50% DR 15 points in Queen of Blades - More blades means more life-on-striking 0 points in Doom - We get this from an amulet. Also the build doesn't really need Doom for damage or leech. 1 point in Blink - +skills will do the rest 10 points in Premeditation max Perfect Being - for the avoid we'll need to survive in melee

Here's what I went with.

Stat Allocation Str - Enough to wear all your Gear. Will be somewhat high since we want to wear a lot of heavy armor to raise our defense. Dex - Everything else. Aim for as high block as you can get. Vit - None Ene - None

If you have PlugY (and you should), you'll be able to reassign stats in-game. You should make use of this handy feature to shift points from Str to Dex as you obtain more and more ubercharms with +Str.

Leveling

I usually play all my characters untwinked until level 100 and then twink Sets/SUs/Great Runewords onto them. Playing through fully untwinked with this character is probably a bad idea, as you won't be able to survive Dest. Duncraig/Toraja/Fauztinville without the uber gear.

This gear works similarly to your end-game gear. Your weapon, helm and belts have fire procs which are boosted by ctc Bloodlust from your shield and ctc Mark of the Wild from your body armor. The shield also has a Fortress proc, which does additional damage which is boosted by Doom procs from your amulet. The gloves and boots give you additional Dexterity that allows you to equip a good claw, as well as Strength for the rest of your gear.

You can use the Unique Creation recipe to turn trash uniques you find into the above uniques. The Sewers in Act 2 in particular drop a lot of uniques. You can also get a lot of uniques from the Ennead Necromancers when you're running Hatred K3kBA for your class-charm.

Play through Hatred on /p8, and shift to /p1 somewhere in early Terror. You shouldn't need to grind any areas to get to 120 provided you don't die much in Destruction. (Here's a little trick - Level up to 119 before you do the Ancients Quest in Act 5. When you complete it, you'll get a free level-up to 120) You might want to kill Death Projector on /p8 in case you're unable to get to 120 through normal leveling. Beacon makes it particularly easy.

Obtaining your end-game gear Taha Great Runes for your helm can be found in Destruction Fauztinville. Some builds that are good at farming it are Retaliators, Pirategirls, Dragonforce 'zons, etc. You can check the guide section for more information. Krys and Auhe Great Runes for your weapon, belt and gloves can be found in Destruction Toraja. Some builds that are good at farming it are Summoner Barbs, Javazons, etc. Read this thread and the guide section for more information.

A lot of your gear will consist of runewords. Ideally you want to squeeze as much Enhanced Damage and Enhanced Defense as possible out of them. Read this thread for how. You may want to reroll the runeword (unsocket with 3 TPs + 3 Perfect Gems and resocket) a few times to get max ED and other high stats.

You should set aside some time for Lem-crafting jewels (Check the jewel-crafting portion of the Cube Recipes documentation to know how). Lem runes can be obtained from Hatred Fauztinville (Remember that you can downgrade runes by cubing them to get the right rune you want!). You should use ilvl 99 jewels while crafting. These drop in all Destruction uberlevels, and are particularly common in Destruction Fauztinville.

The Norrec's Targe SU Shield can be hard to come by, so trade for it if you can't find it. The same goes for the great runes. Check the Pandemonium section of the forum for trade requests.

The amulet is obtained by taking a rare ilvl 99 amulet and then rerolling it with runes. You'll need a lot of runes for this as well as for creating high ED superior armors and weapons. You can farm these in Hatred Fauztinville.

Strategy Always keep Shadow Refuge, Path of Flames and Queen of Blades active (Keeping Shadow Refuge on your left mouse button helps). Cast Bloodlust on yourself if you have Shamanka. Beacon has a long duration, so you won't need to cast it much. Just remember to activate it. Don't forget Blink onto tough mobs first, then Crucify them to death. Stay mobile. Use Hades Gate in situations where you want to stay out of melee range, or to quickly regain life. Path of Flames is a very strong spell, especially with all our +fire spell damage. You can safely deal with a lot of the tougher monsters by running around luring them into the flames. It has a relatively short duration though, so set a hotkey for it near your primary skills (Crucify, Blink, Hades Gate) and cast it whenever it runs out. Similarly, you can also kill tougher mobs by luring them into the spots marked by Beacon. This makes the easier summoning quests trivial.

Challenges

Level Challenges Here's a video by skullcmk showing him doing them. (Just one thing, you won't need as good gear as he has in that video to do it. Just a Shedim "El" Claw with a good TU armor and gemwords/rares for the rest of your gear should be enough. You'll just have to be more careful how many amazons you engage at once. Try not to fight in the large rooms unless you're doing really well.)

Ennead Challenge Should be a breeze with the Fiend "Lum" Runeword Claw. I usually wait until level 78 before I do this. Just run with Shadow Refuge straight to the Necromancer on the bottom right and kill him. You may need to repeat this several times until you get the charm you want. However the time you spend on it is well-spent, as you can get a lot of uniques this way. Here's another video by skullcmk for reference.

Black Road Challenge We're not going to use the Black Road Challenge Reward skill (Way of the Raven) as it doesn't add much damage for us. However the +150 Life reward is nice, so we do this challenge anyway. The first three portions of the challenge are easy and can be done early. For the last two, I suggest leveling to 120 first. The tricky part of the Trial of Blood is ensuring you don't kill a Priestess by mistake. When doing this Trial, do NOT activate Queen of Blades and Beacon at the start of the game. You can repeatedly activate Path of Flames while clearing the path to the Priestesses, but ensure that it is not active while luring the Priestesses themselves. There are many ways to actually do the quest, but I prefer to do it this way: Open a Town Portal somewhere outside the first room, lure Skovos to the entrance of Tran Athulua, and then exit the level. Take the waypoint in Halls of the Dead level 2 back to town, and enter the TP from that end. Next clear your way to Lycander and lure her to where Skovos is. Kill both of them and cube the charm. Alternatively you can kill Lycander as soon as you see her and then take a TP to town, then come back to TA through the Halls of the Dead by taking the waypoint and finally killing Skovos, all within 30 seconds. The Trial of Knowledge is very easy. Just ignore all the monsters and go straight to the Robot Bosses and kill them to collect their brains.

The easier Summoning Ubers (Butcher, Tal Rasha, Akarat, King Koth) can be done in two ways - the hard way, and the cheesy way (summoning them right on a Beacon marker right as the nuke falls). I suggest you at least complete each of them the hard way once before you resort to cheesing them. More fun that way.

The Butcher: Just Crucify him, he should die nearly instantly. If your defense is too low, you may want to run around while he takes damage from Path of Flames and QoB.

Tal Rasha: Summon them in the Valley of Kings, run out immediately into the Lost City. Lure them out one by one. Dodge their spells, then Blink right on top of them and kill them while they're stunned. Keep a TP open just in case you die.

Akarat: Similar to the above quest, you want to summon them in the Kurast Causeway, then immediately run into Upper Kurast. Lure out the minions one by one, making sure to dodge their hammers. You can kill them with Path of Flames alone. Just be sure to engage Akarat while he's near a minion of his. You'll probably die a lot, but it's very satisfying to kill him eventually. Don't forget to keep a TP open in Upper Kurast.

King Koth: Not much here, Shadow Refuge should defend you nicely from their physical damage, and you'll be able to kill them all in no time. Try not to charge into all of them though, they'll stun you and then kill you with Hawk Talon traps.

Lord Alric Jitan: Enter the temple, open a TP. Cast Dark Summoning and immediately enter the TP. Re-enter the area through the Red Portal. Lure out the guardsmen one by one and kill them. You should always back away from them just as they're about to die, or you'll die to their Singularity-on-death procs. Path of Flames can deal the finishing blow when you're out of melee range. When Jitan appears, lure him towards the Red Portal. You might want to leave and re-enter 10 seconds later if he summons too many Fortresses. Then Blink onto him and kill him. You'll have to repeat this a few times to get the charm. Note that you won't be able to cheese this quest with Beacon, as Jitan's Guardsmen are immune to Poison, and Jitan himself is immune to everything as long as he's near his Guardsmen. Once you lure him away though he'll no longer be immune, and then Beacon might help you in killing him. For this quest you might want to make and wear a Dragonheart "Kra" Runeword Body Armor. It will increase your defense significantly.

Legacy of Blood: Having a lot of summons for this quest helps. Make a Dar-Al-Harb "Ix" Runeword Assassin Shield for this, it'll give you a lot of Shadows and Darklings as meatshields. You can also do the first part of the next quest to obtain Edyrem for even more meatshields. Summon all your meatshields, then cast Dark Summoning. Step back so Bartuc and his golems target your summons. Then just start whacking away. Keep an eye open on your summons so you can retreat in case they die.

Judgment Day: For the first part of this quest, you'll need a Dar-Al-Harb shield. Summon all your summons in town, then take the waypoint to the Inner Cloister. Cast Dark Summoning near your summons, then run back so you don't get targeted. Locate Uldyssian among the Dark Edyrem (he's the one with heavier armor) then spam Darklings on him until an Avatar is summoned, then immediately run to the Avatar and kill him. You'll have to ensure that Path of Flames is active all the time while you're waiting for the Avatar to be summoned. A moment's hesitation and all your summons will be dead and the Dark Edyrem will teleport onto you and kill you.

The second part is trickier. Summon 10 Edyrem near the entrance to Jail level 3. Then cast Dark Summoning. When Uldyssian and his minions appear, click on the entrance to Jail 3. If you time it right, a lot of the Dark Edyrem will blink into the Jail. Then go back to the Inner Cloiser. You'll have to repeat this a few times to isolate Uldyssian from his pack.

Once Uldyssian is alone wait for the first Avatar to be summoned. Keep resummoning Edyrem when they die. As soon as the first Avatar shows up, kill him. Now you'll have to wait and hope that another is summoned within 30 seconds, and that its different from the one that was summoned first. Takes a few minutes, but you should manage.

BrotherLaz: I haven't been able to kill him yet, though I hear that a more patient player might be able to do so by entering and leaving the Proving Grounds, using Beacon to kill off his Groupies.

Inarius’ Revenge: Pretty easy. You might want to summon some Edyrem first for tanking.

Dungeon Ubers

Creature of Flame: Both Horazon's Familiar and the Creature of Flame can be stunned with Blink. Do this uber as soon as you find the entrance to it in Destruction.

Infernal Machine: Just run straight in and kill the machine. You might want to be at level 120 so that the elites aren't too much of a problem.

Death Projector: Lure all the mechanics into the room on the top left, then Blink across the wall. Walk down then blink to the right. Lure a single mechanic back to the Projector and then destroy it with Crucify, taking care to dodge the Death Spiral whenever it appears. If you're feeling lazy you can just go straight in and dodge the mechanics and the Death Spiral until a Beacon nuke falls and destroys the Death Projector. More chances of messing up and dying that way though.

Azmodan's Reliquary: High max resistances are a must for this. Wearing a Witchhunter's Hood Set Cap as well as completing the first part of Judgment Day helps. Enter the building and then Blink straight over the wall to your bottom left. You'll find that the room is full of Elites, and Azmodan is among them. Start Crucifying the monster nearest to you while Blink cools down. Then Blink onto Azmodan. You'll be gaining life all the while from life-on-striking. Just be sure to spam Crucify so you get lots of life from Crucify spikes and Fortress procs.

Rathma Square: Summon 10 Edyrem outside the entrance, cast Path of Flames, then enter. Fight your way to Primus, taking the route through the large room on the top. Blink onto him and kill him as soon as you see him. You'll have to repeat this a few times to get the charm.

Cathedral of Vanity: There are several ways you can go about doing this quest. The reckless way: Summon 10 Edyrem in the top room, and then lure all the nuns and Inarius into attacking them. Then Blink straight down and attack the Crystal Ball. Once the Ball is destroyed and the shield falls, the rest of the monsters are easy. The slow and steady way: Make a Lily Runeword ("Jah" in a Circlet), which gives you Charm charges. Lure the nuns and Inarius to the top room, then charm then nuns. Inarius will slowly kill them. Once all the nuns are dead, run in and kill the Crystal Ball. The fastest but riskiest way: Cast Beacon outside the entrance. Wait for about 15 seconds then enter. Run around the Crystal Ball dodging its Death Spiral while all the Nuns, High Priests and Inarius try to kill you. Hope for a nuke to fall near the Crystal Ball and kill it. By the way, no matter the method you choose, you WILL die a lot during this quest. It's a test of patience more than anything.

Toraja: Enter the portal, then summon 10 Edyrem. Blink across the fence to the top right. Kill any Archers whose shields your Edyrem disable. Resummon the Edyrem when they die. Then Blink onto the nearest archer and kill her. Repeat until you near Lilith's position (she's at the very top-most location of the map). Now what you want to do is lure Lilith into the open, not fight her minions while she's nearby across a fence. If she gets into such a position she'll rapidly summon Morlu that fill the screen making it difficult to kill her. So you'll want to keep backing off pulling away all the monsters into the open area and killing them. Eventually Lilith will follow you there. Then summon Edyrem right on top of Lilith until her immunity shield drops. When it does, Blink onto her and Crucify her to death. For this quest you might want to make and wear a Dragonheart "Kra" Runeword Body Armor. It will increase your defense significantly.

Vizjun: A very hard uber, but still doable. The Cruciator lacks the survivability needed to go toe-to-toe against the monsters in there, especially Enforcers which will rip you to shreds the moment you stop moving. But luckily you don't have to. Shadow Refuge makes you extremely fast, so all you need to do is run straight to the MCS, destroy it with a single cast of Purify, and grab the charm as quickly as possible. It's not easy though, the moment you stop running you'll die. Best of luck. The ubercharm helps our build a lot since it's built around a striking modifier. So try your best to obtain it.

Uberlevels

Kurast 3000BA: You're practically invincible here. Just run around killing things in no particular order. Enjoy.

Island of the Sunless Sea: Extremely easy. The regular monsters themselves are no problem and should die before they even get to you. For Malic, you'll have to dodge his Punishers, then Blink onto him and kill him. For Lucion, try and lure him near a gap, then blink across and kill him with Hades Gate/Starburst/Rain of Bombs. Or you could even just kill him in melee. Not a problem really.

Khalimgrad: These guys hit hard and die easy. As long as you don't engage large mobs without stunning them first with Blink you'll do fine. I spent a lot of time here farming Avatars. Rather enjoyable seeing whole screens of enemies die.

Tran Athulua: If your defense is low, you might have trouble dealing with the large rooms where the Priestesses are. But as long as you use Blink and Hades Gate liberally, hide behind your reanimates, lure out archers in small groups, etc. you should do fine.

Fauztinville: Yes, this level is easy. This build is practically built to survive in Fauztinville. With all those monsters on screen, you'll be regaining tons and tons of life every second. And you'll have lots of reanimates to tank for you. Just don't run straight at a pack of Necrobots and expect to live. Always use Blink.

Ghosts of Old Bremmtown: Sadly life-on-striking is useless when you die instantly. And Blink is useless when non-stunned monsters from offscreen can just teleport onto you themselves.

Kingdom of Shadow: Still trying.

Duncraig: Farming the level is relatively easy, the quest itself is not. When clearing large rooms, don't engage the monsters without Blink. Once you've killed a few, it's better to stop entering into melee range at all and just spam Hades Gate to teleport around and kill them, together with Path of Flames. Once all the non-fire-immune monsters are dead, blink onto the survivors and Crucify them to death. Note that as of v1.A9, the Slain Souls in Duncraig are no longer knockback-able. So you can't expect to survive just by spamming Hades Gate at one spot. You'll have to Hades Gate all over the place so the monsters don't get to you. The teleport sections are the hardest. Beacon can help a bit with this, but you'll have to get the timing just right. At every section where you have to teleport, open a TP, wait just as the Beacon is about to appear, and then Blink across the wall. Even if you get surrounded and die the nuke should clear the screen and make it easy to recover your corpse. Lure away Assur and distract him with Edyrem for the last teleport section. The fight with Assur is a lot of fun, and yet quite easy. Just dodge all his fire spells and cast Purify at him repeatedly. You might want to raise your max fire resistance for this by socketing Perfect Bloodstones in your armor.

Heroic Bosses

Bull Prince Rodeo:The hardest part of this is clearing your way to the fort-like structure on the map. The cows hit hard and there are tons and tons of them in the level. Once you've killed a few try to stay out of melee range and kill them solely with Hades Gate, Path of Flames and Queen of Blades. Luckily the cows can be knocked back, unlike the Slain Souls in Duncraig. Try to hide behind your reanimates as well. If BPR finds you while you're doing all of this, you're in a world of trouble. Unless you can make your way to a northern wall (like the one in the fort) you're screwed. Exit and try again. Once you've fought your way to the fort, clear it out as well as a bit of the surrounding area. Then stand slightly below the wall that runs along the top left and cast Dark Summon. You'll have to cast it several times before you actually summon the boss. Making a few Adrenaline Potions to reset the timer after each cast can help to speed up the process. Don't forget to keep Path of Flames active while you're doing this. When Bull Prince Rodeo is finally summoned, just attack him all out with Crucify. He does nearly 0 damage by himself, and you'll regain your lost life instantly. The moment he loses fire resistance he'll die.

Quov Tsin: The trickiest part of this fight is obtaining the right gear. You'll have to craft Gloves and Boots with lots of +all resistances using Stone Shrines. Equip the Event Horizon SU Buckler in your shield slot, and a Witchhunter's Hood on your head. socket them with Perfect Bloodstones, Ambers, Onyxes and Turquoises to get 95 all res and 530+ total res. Read this thread for more info. Next, equip your normal gear and clear out a large portion of the Stony Tomb. Then equip the gear mentioned above and cast Dark Summoning in the middle of the cleared out area. As in the case of Bull Prince Rodeo, you'll need to do this several times before you succeed. I highly recommend crafting a few Adrenaline Potions to speed up the process. Once Quov Tsin is summoned, it's just a matter of attacking him non-stop till he dies. Be sure to keep drinking Health Potions in case your need it. Use Blink to follow him around as he teleports away. One thing to note is that neither Crucify nor Fortress will target him, due to his homing-jam. Just use Shadow Refuge to attack him.

Belial: See below.

Astrogha: Yeeaah, this one's too much for me.

Things to do after Uberquests and Challenges Once you've completed the above uberquests and challenges, you can put your character to work farming items, ubercharms, signets and trophies. K3kBA - Good place to farm lots of Set items for your future characters, as well as to convert into Signets of Learning. Khalimgrad - The Zakarum's Avatars on this level drop a lot of Sets and SUs. You can quickly Blink your way to each of them and kill them for easy loot. Duncraig - This is the best place to find SUs. Keep your eyes open for Barrels though. You might want to stay out of melee range of large mobs here - use Hades Gate and Path of Flames to your advantage. Fauztinville - The Cruciator can clear this area at moderate speed, so you can farm it for Great Runes. (She's not particularly good at Toraja though, since she can't really help the Edyrem survive/kill faster. Better go with one of the other builds mentioned above.) Scroll of Kings/Sacred Worldstone Key ubercharms - These charms come with character-specific skills, and some of them are highly sought after for certain builds. With Beacon, farming the right charm you need is easy. Akarat Trophy - Gives a nice 5% boost to Life and Mana. Just summon them right as the Beacon falls. Will take you about 25-50 mins to get it, less if you're lucky. Fool's Gold ubercharms - Certain reanimates on this charm are much better than others and highly sought after, such as Void Archons, Destroyer Shamans, Mountain Gods, etc. You can farm Bull Prince Rodeo for them, just be sure to summon him in a safe place as mentioned above.

Magic Find When farming K3kBA, Duncraig, Khalimgrad etc. for Sets and SUs, you should try and get some Magic Find (MF). Anything more than 400 is excessive, although you'll get good drops with just 300-400 as well. An easy way to get lots of MF is to replace your body armor with the Hratli's Craft SU Ring Mail, and socket it with 6 Lum runes, for a total of +245 MF. You can also socket your shield with 4 Perfect Turquoises for +100 MF. When doing so, you might find that your resists fall below the max. Replace your boots with the Stone-craft boots you made to kill Quov Tsin to make up for the deficit.

Useful Links

LFAQ LFAQ!

Maps Map of Fauztinville by aerial Map of Duncraig by ncc Map of Vizjun by theworldismuchtoosmall.

Changelog

Aug 05 - Posted guide Aug 06 - Added a changelog, added a note about life leech under Aug 10 - Modified gear section to include alternate ways to prebuff for damage and spell damage Sept 01 - Added a video by skullcmk showing him doing the Level Challenges with a Cruciator. Sept 02 - Added another video by skullcmk, this time for the Ennead Challenge. Sept 03 - Added an extensive section on how to kill Belial (see below).

This is a bit more involved than the other Heroic Bosses, so I'll go into depth here. Belial uses several spells, the most notable of which is his Life Drain Nova (a nova that looks like vertical bars flying outward). You'll learn to fear the power of this awesome spell. His other spells, a "Rat-nova" and a Liche-form-like blast of Punishers do negligible damage compared to the other one. The Life Drain Nova applies Life Drain to you, which very rapidly reduces your life to 1, but cannot kill you, like Poison spells. However, unlike Poison, there's no way to reduce the rate at which life is drained. Now even though Belial's other spells do negligible damage, when combined with Life Drain they can be deadly. Belial also uses a Pounce attack to chase you around. Whenever he Pounces, he summons a ring of rat "Henchmen" around himself. The Henchmen rapidly fire Punishers at you. With enough Poison resistance, the damage can be mitigated. The Henchmen also have comparatively low life. You should be able to kill them in 1-2 seconds after they're summoned. Last but not the least, Belial spawns with a group of "Ratfinks". These tiny rats cannot be targeted or damaged in anyway, and they do enormous damage per hit. The only way to deal with them is to separate them from Belial and fight him alone. More on this later.

Gear In order to survive an encounter with Belial, we will need two things.

High Max Poison Resistance Increased Healing Rate From Potions You will need to push your Poison Resistance to 95. The easiest way to do this is to use a Witchhunter's Hood Set Cap and a pair of crafted boots, both socketed with Perfect Turquoises. Increased Healing Rate From Potions can be obtained from Mystic Orbs. You don't need much, I used 30% from my crafted boots.

Strategy

Positioning

Every monster group the game loads in the Icy Cellar has a 1% chance of being replaced by Belial. Depending on where Belial spawns (if at all), the difficulty of the run varies. As I said above, Belial always spawns with a group of Ratfinks, and uses Pounce to chase you. Ideally you want to fight him away from the Ratfinks, as they can very easily kill you in 2-3 hits. If you exit the Icy Cellar at the exact moment Belial pounces, he will follow you into the Ancient Way. This can be useful to separate him from Ratfink when he spawns near the entrance. Ideally, Belial will spawn on the other side of a river, and Pounce to you leaving his Ratfink behind. In both cases, you want to fight Belial near an exit - if he spawns near the exit to the Icy Cellar, pull him into the Ancient Way, and then lure him to the other nearest exit. Otherwise just fight him at the Icy Cellar entrance. If you don't find Belial by the time you've cleared most of the Icy Cellar, save and exit, and try again. Using Dark Summoning to summon him isn't a good idea, as he'll spawn with Ratfinks right on top of you and you won't be able to use Hades Gate or Blink to run from them because of the timer.

The Battle Now that you've lured Belial to an exit, use the exit and open a portal on the other side. Make sure Belial doesn't follow you - he only Pounces if you're far from him. If he's standing right next to the exit he won't follow you. If he does, re-enter and open the TP on the other side. Use the TP to go back to town, go to Malah, click Trade, and drink all the potions in your belt. Shift + right click on the potion she's selling to refill your belt. Drink all of the ones you just bought. Repeat until you've drunk 12-16 potions. This is called "Potion Stacking". Now you'll be constantly healing for the next minute or so. Re-enter the TP, open a new one. Cast Path of Flames (and Bloodlust and Mark of the Wild if you have them). Now return back to where Belial is and attack him with Crucify. If he spawns any Henchmen, kill them as quickly as possible. Keep an eye open for the Life Drain Nova. If you see him cast it, immediately head for the exit. If Belial follows you through, go back through the exit again and open a TP on the other side. Wait out the duration of the Life Drain. It shouldn't take more than 5-10 seconds. Once the drain ends, re-cast all your buffs and go back in. You'll also need to periodically go back to town to re-stack potions. If you die during the fight, use the TP to go back and recover your corpse. Once you have it, immediately leave and go back to town so you can drink up on potions again, as well as re-cast Queen of Blades, Beacon, Path of Flames, Bloodlust, and Mark of the Wild (phew!). Depending on how often Belial's Fire Immunity drops and how often you die, the battle can take anywhere from 1 minute to 20 minutes.

Belial doesn't have great drops, but you can farm him for the skill-charms he drops. Best of luck.